prepare you cake pan
Preheat your oven to 170°C / 340°F. Grease a 20 cm / 8-inch springform cake pan. Brush the butter generously on the entire inside of the pan. Cut a piece of baking paper to fit the bottom of the pan and place it on the bottom of your greased cake pan.
Place a saucepan with about 1/2 cup of water over medium-low heat. Add chocolate, butter, sugar and 1/4 tsp of salt to a heat-proof bowl. Place the bowl over the saucepan with water and let the ingredients melt, stirring occasionally with a wire whisk. Remove from the heat and add brown sugar, all-purpose flour and ground almonds to the mixture. Stir to combine using a spatula. Add the heavy cream (or milk), eggs, rum and rose water (optional). Stir vigorously with a wire whisk or spatula until the mixture is shiny and smooth.
Pour the chocolate mixture into your prepared cake pan. Cover with aluminum foil (make sure the foil does not touch the food). Place in the preheated oven and bake for 45 - 50 minutes at 170°C / 340°F. Let the cake cool in the pan, then transfer it to a fridge for about 2 - 3 hours to set, then serve.
Whip your whipping cream with vanilla paste to soft peaks. Keep the whipped cream chilled until needed. Remove your single layer chocolate cake from the fridge 20 minutes before serving. Sprinkle with dutch process cocoa powder and serve with a generous dollop of whipped cream and a tablespoon of fresh raspberries. Keep your cake chilled in a fridge for up to 4 days.